Mar 19 2013

Evolved to Gamble

It is tempting to make arguments about how and why particular aspects of human psychology evolved. I will not be getting into an evolutionary psychology discussion in this post, I will just say I find such arguments offer a plausible framework for understanding human psychology, regardless of whether you think they can be scientifically tested.

A recent example is a paper by researchers at McMaster University. The title of their press release  reads: It’s in the cards: Human evolution influences gamblers’ decisions, study shows. 

The study actually says nothing about human evolution. It simply demonstrates an aspect of human behavior – the evolutionary explanation is pure speculation, not tested or demonstrated in the study itself.

Nevertheless, the study is interesting. It involved gambling behavior. Subjects were given money to gamble on which target would be next illuminated. The targets were illuminated at random, so any target had an equal chance of being the winning bet on any round.

The study found that subjects were more likely to change the target they bet on when their current target won, or after the target of another player won. In other words, they made their bets with the implicit assumption that the same target would not be illuminated twice in a row, even though that reasoning had absolutely no basis in reality. The subjects were not given any information that would make them think this was the case, in fact what they were told directly contradicts it. Also, the experience of playing would not have led to this conclusion, so again, it was something that was simply assumed by the subjects.

This is simply the well-known gambler’s fallacy – the sense that if you toss a fair coin and it comes up heads four or five times in a row, it is then “due” to come up tails. Of course, if the coin is truly fair then the next toss is still 50% likely to come up heads and 50% tails. Past events have no influence on the outcome of the next toss. Our intuitive sense is profoundly wrong in this case.

Gamblers sometime follow the opposite logic. On the roulette table, for example, they may play numbers that have come up before on the logic that they are on a streak, or that something is making them more likely to come up. At the same time they can play numbers that have not come up recently because they are “due” – and these contradictory bits of logic can coexist in the eager gambler.

The lead author, Jim Lyons, is quoted as saying:

“The results of our work suggest, perhaps for the first time, that certain aspects of problem gambling behaviour may be related to hard-wired, basic neurobiological factors related to how we direct our attention.”

This is a reasonable conclusion to draw from the study, and is consistent with prior research – these gambling behaviors appear to be hard-wired. Gambling itself appears to be culturally universal, but there isn’t much data on cultural vs innate factors in problem gambling across cultures. There is some evidence that the Chinese have greater problem gambling, with one review finding:

“Chinese gamblers exhibit severer cognitive errors, stronger risk-taking tendency and higher level of stress and depression, which explained the common findings of literature that Chinese have higher gambling and problem gambling rates than other ethnic groups.”

It seems that there are both universal and culture specific beliefs that contribute to gambling – those that involve luck and the illusion of control. In order to conclude that the gambler’s fallacy is evolved rather than learned or cultural it would need to be demonstrated to be culturally universal, at least to a degree. It seems the evidence is pointing in this direction, but is not completely confirmed at this point.

Where the discussion of this study gets into speculation – perfectly plausible and reasonable speculation, but speculation all the same, is when the press release attempts to explain why humans evolved the gambler’s fallacy heuristic. The press release says:

“They found that, like our ancestors, the gamblers relied on their past experiences to predict what might happen in the future. “

and then quoting psychologist Dan Weeks:

“Humans make rational decisions on a day-to-day basis based on experience. Think about someone picking apples in an orchard. Once the apples from the first tree are picked, it is a rational decision to move on to the next tree.”

It is certainly plausible that the foraging and hunting behavior of human ancestors contributed to the evolution of the gambler’s fallacy – don’t expect to get lucky in the same place twice, at least not soon. We just need to recognize that this is speculation, and not something we can derive from the evidence presented in this study.

In trying to understand the foibles of human cognition and behavior it is a useful idea that humans evolved in an environment that is very different from our modern civilization. We did not evolve with the stimulations and temptations presented by casinos. Similarly we did not evolve with virtually unlimited easy access to high caloric foods.

Psychological experiments have demonstrated a number of errors in thinking that people generally make. We have hyperactive agency detection, we have a “supersense” – a notion that living things have an essence, and even inanimate objects can possess an unseen property or significance, we tend to make assumptions about cause and effect, we seen patterns where they don’t exist, and find it difficult to accept that coincidences happen for no particular reason.

The gambler’s fallacy fits snugly into this suite of cognitive flaws and biases – the powerful assumption that past events influence future events, even when there is no plausible way that they can, and even when the system is designed to be as certain as possible that they don’t (which is the case with casinos and lotteries). We invent magical explanations, like luck, to explain what we feel to be right but know to be wrong.

It makes sense that this all evolved under some set of selective pressures. It would be interesting to study that directly, and perhaps someone is clever enough to figure out how. This current study, however, does not address the question.

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